Neutron stars can hide an invisible 'doughnut' of a supermassive scalar field inside them. It changes their mass and radius, making them pretend to be quark or hybrid stars, yet remains invisible to telescopes. The discovery explains strange objects that previously baffled astronomers.
🎯 The 'doughnut' effect allows a neutron star to exist in two stable states with different masses at once—as if two different objects coexist in a single body.